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module history
implicit none
type :: location
character(1024)::url
type(location), pointer::next
end type
contains
function last_location(first_location)
implicit none
type(location), pointer::first_location
type(location), pointer::last_location
if(.not. associated(first_location)) then
last_location => null()
else
last_location => first_location
do while(associated(last_location%next))
last_location => last_location%next
end do
end if
end function last_location
function add_location(first_location, url) result(head)
implicit none
type(location), pointer::first_location
type(location), pointer::head
character(*), intent(in)::url
type(location), pointer::last
! Check if it is our first location
if(.not. associated(first_location)) then
allocate(first_location)
first_location%next => null()
first_location%url = url
else
last => last_location(first_location)
allocate(last%next)
last => last%next
last%next => null()
last%url = url
end if
head => first_location
end function add_location
subroutine back_location(first_location, url)
implicit none
type(location), pointer::first_location
character(*), intent(out)::url
type(location), pointer::last, new_last
url = " "
last => last_location(first_location)
if(associated(last)) then
url = last%url
if(.not. associated(last, first_location)) then
new_last => first_location
do while(.not. associated(new_last%next, last))
new_last => new_last%next
end do
new_last%next => null()
deallocate(last)
end if
end if
end subroutine back_location
end module history
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